def create_model(input_shape, anchors, num_classes, load_pretrained=True, freeze_body=2,
weights_path='model_data/yolo_weights.h5'):
'''create the training model'''
K.clear_session() # get a new session
image_input = Input(shape=(None, None, 3))
h, w = input_shape
num_anchors = len(anchors)
y_true = [Input(shape=(h//{0:32, 1:16, 2:8}[l], w//{0:32, 1:16, 2:8}[l], \
num_anchors//3, num_classes+5)) for l in range(3)]
model_body = yolo_body(image_input, num_anchors//3, num_classes)
print('Create YOLOv3 model with {} anchors and {} classes.'.format(num_anchors, num_classes))
if load_pretrained:
model_body.load_weights(weights_path, by_name=True, skip_mismatch=True)
print('Load weights {}.'.format(weights_path))
if freeze_body in [1, 2]:
# Freeze darknet53 body or freeze all but 3 output layers.
num = (185, len(model_body.layers)-3)[freeze_body-1]
for i in range(num): model_body.layers[i].trainable = False
print('Freeze the first {} layers of total {} layers.'.format(num, len(model_body.layers)))
for y in range(-3, 0):
model_body.layers[y].name = "conv2d_output_" + str(h//{-3:32, -2:16, -1:8}[y])
model_loss = Lambda(yolo_loss, output_shape=(1,), name='yolo_loss',
arguments={'anchors': anchors, 'num_classes': num_classes, 'ignore_thresh': 0.5})(
[*model_body.output, *y_true])
model = Model([model_body.input, *y_true], model_loss)
return model
def _main_(args):
config_path = args.conf
print("load config")
with open(config_path) as config_buffer:
config = json.loads(config_buffer.read())
###############################
# Create the validation generator
###############################
valid_ints, labels = parse_voc_annotation(
config['valid']['valid_annot_folder'],
config['valid']['valid_image_folder'],
config['valid']['cache_name'],
config['model']['labels']
)
labels = labels.keys() if len(config['model']['labels']) == 0 else config['model']['labels']
labels = sorted(labels)
print("valid generator")
valid_generator = BatchGenerator(
instances = valid_ints,
anchors = config['model']['anchors'],
labels = labels,
downsample = 32, # ratio between network input's size and network output's size, 32 for YOLOv3
max_box_per_image = 0,
batch_size = config['train']['batch_size'],
min_net_size = config['model']['min_input_size'],
max_net_size = config['model']['max_input_size'],
shuffle = True,
jitter = 0.0,
norm = normalize
)
###############################
# Load the model and do evaluation
###############################
os.environ['CUDA_VISIBLE_DEVICES'] = config['train']['gpus']
#ignore no training configuration
#infer_model = load_model(config['train']['saved_weights_name'])
infer_model = yolo_body(Input(shape=(None,None,3)), 3 , 20) #load_model(config['train']['saved_weights_name'])
#infer_model = tiny_yolo_body(Input(shape=(None,None,3)), 3 , 20)
infer_model.load_weights(config['train']['saved_weights_name'])
print(config['train']['saved_weights_name'])
print("get mAp for All classes")
# compute mAP for all the classes
average_precisions = evaluate(infer_model, valid_generator)
# print the score
for label, average_precision in average_precisions.items():
print(labels[label] + ': {:.4f}'.format(average_precision))
print('mAP: {:.4f}'.format(sum(average_precisions.values()) / len(average_precisions)))
def generate(self):
model_path = os.path.expanduser(self.model_path)
assert model_path.endswith('.h5'), 'Keras model or weights must be a .h5 file.'
# Load model, or construct model and load weights.
num_anchors = len(self.anchors)
num_classes = len(self.class_names)
is_tiny_version = num_anchors==6 # default setting
try:
self.yolo_model = load_model(model_path, compile=False)
except:
self.yolo_model = tiny_yolo_body(Input(shape=(None,None,3)), num_anchors//2, num_classes) \
if is_tiny_version else yolo_body(Input(shape=(None,None,3)), num_anchors//3, num_classes)
self.yolo_model.load_weights(self.model_path) # make sure model, anchors and classes match
else:
assert self.yolo_model.layers[-1].output_shape[-1] == \
num_anchors/len(self.yolo_model.output) * (num_classes + 5), \
'Mismatch between model and given anchor and class sizes'
print('{} model, anchors, and classes loaded.'.format(model_path))
# Generate colors for drawing bounding boxes.
hsv_tuples = [(x / len(self.class_names), 1., 1.)
for x in range(len(self.class_names))]
self.colors = list(map(lambda x: colorsys.hsv_to_rgb(*x), hsv_tuples))
self.colors = list(
map(lambda x: (int(x[0] * 255), int(x[1] * 255), int(x[2] * 255)),
self.colors))
np.random.seed(10101) # Fixed seed for consistent colors across runs.
np.random.shuffle(self.colors) # Shuffle colors to decorrelate adjacent classes.
np.random.seed(None) # Reset seed to default.
# Generate output tensor targets for filtered bounding boxes.
self.input_image_shape = K.placeholder(shape=(2, ))
if self.gpu_num>=2:
self.yolo_model = multi_gpu_model(self.yolo_model, gpus=self.gpu_num)
boxes, scores, classes = yolo_eval(self.yolo_model.output, self.anchors,
len(self.class_names), self.input_image_shape,
score_threshold=self.score, iou_threshold=self.iou)
return boxes, scores, classes
def data_generator(annotation_lines, batch_size, input_shape, anchors,
num_classes):
'''data generator for fit_generator'''
num_anchors = len(anchors)
image_input = Input(shape=(416, 416, 3))
model = yolo_body(image_input, num_anchors // 3, num_classes)
model.load_weights("model_data/trained_weights_final.h5")
n = len(annotation_lines)
i = 0
while True:
image_data = []
box_data = []
for b in range(batch_size):
if i == 0:
np.random.shuffle(annotation_lines)
image, box = get_random_data(annotation_lines[i],
input_shape,
random=True)
image_data.append(image)
box_data.append(box)
i = (i + 1) % n
image_data = np.array(image_data)
box_data = np.array(box_data)
#y_true = preprocess_true_boxes(box_data, input_shape, anchors, num_classes)
# print(image_data.shape)
y_true = model.predict(image_data)
# print("d")
# print(y_true[0].shape)
# print(y_true[1].shape)
# print(y_true[2].shape)
# y_true[0] = y_true[0].reshape(y_true[0].shape[0], y_true[0].shape[1], y_true[0].shape[2], 3 , y_true[0].shape[3]//3 )
# y_true[1] = y_true[1].reshape(y_true[1].shape[0], y_true[1].shape[1], y_true[1].shape[2], 3 , y_true[1].shape[3]//3 )
# y_true[2] = y_true[2].reshape(y_true[2].shape[0], y_true[2].shape[1], y_true[2].shape[2], 3 , y_true[2].shape[3]//3 )
yield [image_data, *y_true] #, np.zeros(batch_size)
def _main():
train_path = '2007_train.txt'
val_path = '2007_val.txt'
# test_path = '2007_test.txt'
log_dir = 'logs/000/'
classes_path = 'class/voc_classes.txt'
anchors_path = 'anchors/yolo_anchors.txt'
class_names = get_classes(classes_path)
num_classes = len(class_names)
anchors = get_anchors(anchors_path)
num_anchors = len(anchors)
input_shape = (416,416) # multiple of 32, hw
with open(train_path) as f:
train_lines = f.readlines()
#s
with open(val_path) as f:
val_lines = f.readlines()
# with open(test_path) as f:
# test_lines = f.readlines()
num_anchors = len(anchors)
image_input = Input(shape=(416, 416, 3))
model = yolo_body(image_input, num_anchors//3, num_classes)
model.load_weights("model_data/trained_weights_final.h5")
yolo3 = Reshape((13, 13, 3, 25))(model.layers[-3].output)
yolo2 = Reshape((26, 26, 3, 25))(model.layers[-2].output)
yolo1 = Reshape((52, 52, 3, 25))(model.layers[-1].output)
model = Model( inputs= model.input , outputs=[yolo3,yolo2,yolo1] )
batch_size = 1
# create an hdf5 file
train_size = len(train_lines)
print( "total "+ str(len(train_lines)) + " loop "+ str( train_size ) )
with h5py.File("train_logits.h5",'w') as f:
# create a dataset for your movie
img = f.create_dataset("img_data", shape=( train_size, 416, 416, 3)) #len(train_lines)
bbox = f.create_dataset("big_logits", shape=( train_size, 13, 13, 3, 25))
mbox = f.create_dataset("medium_logits", shape=( train_size , 26, 26, 3, 25))
sbox = f.create_dataset("small_logits", shape=( train_size , 52, 52, 3, 25))
i = 0
for logits in tqdm( data_generator_wrapper(train_lines, batch_size, input_shape, anchors, num_classes,model) ) :
img[i] = logits[0][0] # np.random.randint(255, size=(416, 416, 3)) #
bbox[i] = logits[1][0]
mbox[i] = logits[2][0]
sbox[i] = logits[3][0]
i+=1
if i>= train_size:#(len(train_lines)) :
break
'''
fp = h5py.File('train_logits.h5','r')
#train_logits = []
print(fp["img_data"][0].shape)
print(fp["big_logits"][1].shape)
boxan = np.where(fp["big_logits"][1][:,:,:,4] > 0.3 )
print(boxan)
print(fp["medium_logits"][1].shape)
boxan = np.where(fp["medium_logits"][1][:,:,:,4] > 0.3 )
print(boxan)
print(fp["small_logits"][1].shape)
boxan = np.where(fp["small_logits"][1][:,:,:,4] > 0.3 )
print(boxan)
'''
val_size = len(val_lines)
print( "total "+ str(len(val_lines)) + " loop "+ str( val_size ) )
with h5py.File("val_logits.h5",'w') as f:
# create a dataset for your movie
img = f.create_dataset("img_data", shape=( val_size, 416, 416, 3)) #
bbox = f.create_dataset("big_logits", shape=( val_size, 13, 13, 3, 25))
mbox = f.create_dataset("medium_logits", shape=( val_size, 26, 26, 3, 25))
sbox = f.create_dataset("small_logits", shape=( val_size, 52, 52, 3, 25))
# fill the 10 frames with a random image
i = 0
for logits in tqdm( data_generator_wrapper(val_lines, batch_size, input_shape, anchors, num_classes,model) ) :
img[i] = logits[0][0] # np.random.randint(255, size=(416, 416, 3)) #
bbox[i] = logits[1][0]
mbox[i] = logits[2][0]
sbox[i] = logits[3][0]
i+=1
if i>= val_size:#(len(val_lines)) :
break
def _main():
train_path = '2007_train.txt'
val_path = '2007_val.txt'
# test_path = '2007_test.txt'
log_dir = 'logs/logits_only_000/'
classes_path = 'class/voc_classes.txt'
anchors_path = 'anchors/yolo_anchors.txt'
class_names = get_classes(classes_path)
num_classes = len(class_names)
anchors = get_anchors(anchors_path)
input_shape = (416, 416) # multiple of 32, hw
is_tiny_version = len(anchors) == 6 # default setting
if is_tiny_version:
model = create_tiny_model(
input_shape,
anchors,
num_classes,
freeze_body=2,
weights_path='model_data/tiny_yolo_weights.h5')
else:
model = create_model(
input_shape,
anchors,
num_classes,
freeze_body=2,
weights_path='model_data/trained_weights_final_mobilenetv2.h5'
) # make sure you know what you freeze
logging = TensorBoard(log_dir=log_dir)
checkpoint = ModelCheckpoint(
log_dir + 'ep{epoch:03d}-loss{loss:.3f}-val_loss{val_loss:.3f}.h5',
monitor='val_loss',
save_weights_only=True,
save_best_only=True,
period=3)
reduce_lr = ReduceLROnPlateau(monitor='val_loss',
factor=0.1,
patience=3,
verbose=1)
early_stopping = EarlyStopping(monitor='val_loss',
min_delta=0,
patience=10,
verbose=1)
with open(train_path) as f:
train_lines = f.readlines()
with open(val_path) as f:
val_lines = f.readlines()
# with open(test_path) as f:
# test_lines = f.readlines()
# train_lines = np.load('train_logits.npy')[()]
# val_lines = np.load('val_logits.npy')[()]
num_val = int(len(train_lines))
num_train = int(len(val_lines))
#declare model
num_anchors = len(anchors)
image_input = Input(shape=(416, 416, 3))
teacher = yolo_body(image_input, num_anchors // 3, num_classes)
teacher.load_weights("model_data/trained_weights_final.h5")
# return the constructed network architecture
# class+5
yolo3 = Reshape((13, 13, 3, 25))(teacher.layers[-3].output)
yolo2 = Reshape((26, 26, 3, 25))(teacher.layers[-2].output)
yolo1 = Reshape((52, 52, 3, 25))(teacher.layers[-1].output)
teacher = Model(inputs=teacher.input, outputs=[yolo3, yolo2, yolo1])
teacher._make_predict_function()
# Train with frozen layers first, to get a stable loss.
# Adjust num epochs to your dataset. This step is enough to obtain a not bad model.
if True:
model.compile(
optimizer=Adam(lr=1e-3),
loss={
# use custom yolo_loss Lambda layer.
'yolo_loss': lambda y_true, y_pred: y_pred
})
batch_size = 2 #16#32
meanAP = AveragePrecision(
data_generator_wrapper(val_lines, 1, input_shape, anchors,
num_classes, teacher), num_val, input_shape,
len(anchors) // 3, anchors, num_classes)
print('Train on {} samples, val on {} samples, with batch size {}.'.
format(num_train, num_val, batch_size))
model.fit_generator(data_generator_wrapper(train_lines, batch_size,
input_shape, anchors,
num_classes, teacher),
steps_per_epoch=max(1, num_train // batch_size),
validation_data=data_generator_wrapper(
val_lines, batch_size, input_shape, anchors,
num_classes, teacher),
validation_steps=max(1, num_val // batch_size),
epochs=30,
initial_epoch=0,
callbacks=[logging, checkpoint, meanAP])
model.save_weights(log_dir +
'distillation_mobilenet_trained_weights_stage_1.h5')
# Unfreeze and continue training, to fine-tune.
# Train longer if the result is not good.
if True:
for i in range(len(model.layers)):
model.layers[i].trainable = True
model.compile(optimizer=Adam(lr=1e-4),
loss={
'yolo_loss': lambda y_true, y_pred: y_pred
}) # recompile to apply the change
print('Unfreeze all of the layers.')
batch_size = 2 #16#32 note that more GPU memory is required after unfreezing the body
meanAP = AveragePrecision(
data_generator_wrapper(val_lines, 1, input_shape, anchors,
num_classes, teacher), num_val, input_shape,
len(anchors) // 3, anchors, num_classes)
print('Train on {} samples, val on {} samples, with batch size {}.'.
format(num_train, num_val, batch_size))
model.fit_generator(
data_generator_wrapper(train_lines, batch_size, input_shape,
anchors, num_classes, teacher),
steps_per_epoch=max(1, num_train // batch_size),
validation_data=data_generator_wrapper(val_lines, batch_size,
input_shape, anchors,
num_classes, teacher),
validation_steps=max(1, num_val // batch_size),
epochs=60,
initial_epoch=30,
callbacks=[logging, checkpoint, reduce_lr, early_stopping, meanAP])
model.save_weights(log_dir +
'distillation_mobilenet_trained_weights_final.h5')
def _main():
train_path = '2007_train.txt'
val_path = '2007_val.txt'
test_path = '2007_test.txt'
#log_dir = 'logs/logits_only_000/'
classes_path = 'class/voc_classes.txt'
anchors_path = 'anchors/yolo_anchors.txt'
class_names = get_classes(classes_path)
num_classes = len(class_names)
anchors = get_anchors(anchors_path)
input_shape = (416,416) # multiple of 32, hw
with open(train_path) as f:
train_lines = f.readlines()
with open(val_path) as f:
val_lines = f.readlines()
with open(test_path) as f:
test_lines = f.readlines()
num_val = int(len(train_lines))
num_train = int(len(val_lines))
num_test = int(len(test_lines))
#declare model
num_anchors = len(anchors)
image_input = Input(shape=(416, 416, 3))
eval_model = yolo_body(image_input, num_anchors//3, num_classes)
eval_model.load_weights("model_data/trained_weights_final.h5")
# return the constructed network architecture
# class+5
yolo3 = Reshape((13, 13, 3, 25))(eval_model.layers[-3].output)
yolo2 = Reshape((26, 26, 3, 25))(eval_model.layers[-2].output)
yolo1 = Reshape((52, 52, 3, 25))(eval_model.layers[-1].output)
eval_model = Model( inputs= eval_model.input , outputs=[yolo3,yolo2,yolo1] )
eval_model._make_predict_function()
batch_size = 1
all_detections = [ [] for i in range(num_classes) ]
all_annotations = [ [] for i in range(num_classes) ]
count_detections = [ [0 for i in range(num_classes)] for i in range(3) ]
num_layers = len(anchors)//3
datagen = data_generator_wrapper(test_lines, batch_size, input_shape, anchors, num_classes,eval_model)
print( "{} test data".format(num_test) )
for n in tqdm( range(num_test) ):#num_test
img,flogits,mlogits = next(datagen)
for l in range(num_layers):
#print( "layer" + str(l) )
arrp = flogits[l]
box = np.where(arrp[...,4] > 0 )
box = np.transpose(box)
for i in range(len(box)):
#print("obj" + str(i) )
#detection_label = np.argmax( flogits[l][tuple(box[i])][5:])
annotation_label = np.argmax( flogits[l][tuple(box[i])][5:])
#print( "{} ({}) {} == ({}) {} ".format(l, detection_label, class_names[ detection_label ] ,annotation_label, class_names[ annotation_label ] ) )
all_detections[annotation_label].append( mlogits[l][tuple(box[i])] )
all_annotations[annotation_label].append( flogits[l][tuple(box[i])] )
count_detections[l][annotation_label] +=1
print(len(all_detections) )
print(len(all_annotations) )
print(count_detections)
iou_thres = 0.5
conf_thres = 0.5
average_precisions = {}
for label in tqdm( range( num_classes ) ) :
false_positives = np.zeros((0,))
true_positives = np.zeros((0,))
scores = np.zeros((0,))
num_detect = len( all_detections[label] )
for det in range( num_detect ):
detect_box = all_detections[label][det][...,0:4]
detect_conf = all_detections[label][det][...,4]
detect_label = np.argmax( all_detections[label][det][...,5:] )
annot_box = all_annotations[label][det][...,0:4]
annot_conf = all_annotations[label][det][...,4]
detect_label = np.argmax( all_detections[label][det][...,5:] )
iou = numpy_box_iou( detect_box , annot_box)
scores = np.append(scores, detect_conf )
if( iou > iou_thres and detect_conf > conf_thres and (label == detect_label ) ):
#print( best_iou[tuple(box[i])] )
print("pos")
false_positives = np.append(false_positives, 0)
true_positives = np.append(true_positives, 1)
else:
print("neg")
false_positives = np.append(false_positives, 1)
true_positives = np.append(true_positives, 0)
indices = np.argsort(-scores)
false_positives = false_positives[indices]
true_positives = true_positives[indices]
print(true_positives)
false_positives = np.cumsum(false_positives)
true_positives = np.cumsum(true_positives)
print(true_positives)
recall = true_positives / num_detect
print( recall )
precision = true_positives / np.maximum(true_positives + false_positives, np.finfo(np.float64).eps)
print( precision )
average_precision = compute_ap(recall, precision)
average_precisions[label] = average_precision
print(average_precisions)
for label, average_precision in average_precisions.items():
print(class_names[label] + ': {:.4f}'.format(average_precision))
print('mAP: {:.4f}'.format(sum(average_precisions.values()) / len(average_precisions)))
'''
from keras.applications.mobilenet import MobileNet
#from model.yolo3 import tiny_yolo_body
#from model.small_mobilenets2 import yolo_body
#from model.medium_darknet import yolo_body
#from model.mobilenet import yolo_body
from model.yolo3 import yolo_body
run_meta = tf.RunMetadata()
with tf.Session(graph=tf.Graph()) as sess:
K.set_session(sess)
#net = MobileNet(alpha=.75, input_tensor=tf.placeholder('float32', shape=(1,32,32,3)) )
#net = MobileNet(input_tensor=tf.placeholder('float32', shape=(1,416,416,3)) ,weights='imagenet')
image_input = Input(shape=(416, 416, 3))
#net = tiny_yolo_body(image_input, 3 , 20)
net = yolo_body(image_input, 3, 20)
opts = tf.profiler.ProfileOptionBuilder.float_operation()
flops = tf.profiler.profile(sess.graph,
run_meta=run_meta,
cmd='op',
options=opts)
opts = tf.profiler.ProfileOptionBuilder.trainable_variables_parameter()
params = tf.profiler.profile(sess.graph,
run_meta=run_meta,
cmd='op',
options=opts)
print("floatops _ {:,} totalparams _ {:,}".format(flops.total_float_ops,
params.total_parameters))
def _main():
train_path = '2007_train.txt'
val_path = '2007_val.txt'
# test_path = '2007_test.txt'
log_dir = 'logs/000/'
classes_path = 'class/voc_classes.txt'
anchors_path = 'anchors/yolo_anchors.txt'
class_names = get_classes(classes_path)
num_classes = len(class_names)
anchors = get_anchors(anchors_path)
input_shape = (416, 416) # multiple of 32, hw
is_tiny_version = len(anchors) == 6 # default setting
if is_tiny_version:
model = create_tiny_model(
input_shape,
anchors,
num_classes,
freeze_body=2,
weights_path='model_data/tiny_yolo_weights.h5')
else:
model = create_model(
input_shape,
anchors,
num_classes,
freeze_body=2,
weights_path='model_data/trained_weights_final_mobilenetv2.h5'
) # make sure you know what you freeze
logging = TensorBoard(log_dir=log_dir)
checkpoint = ModelCheckpoint(
log_dir + 'ep{epoch:03d}-loss{loss:.3f}-val_loss{val_loss:.3f}.h5',
monitor='val_loss',
save_weights_only=True,
save_best_only=True,
period=3)
reduce_lr = ReduceLROnPlateau(monitor='val_loss',
factor=0.1,
patience=3,
verbose=1)
early_stopping = EarlyStopping(monitor='val_loss',
min_delta=0,
patience=10,
verbose=1)
with open(train_path) as f:
train_lines = f.readlines()
with open(val_path) as f:
val_lines = f.readlines()
# with open(test_path) as f:
# test_lines = f.readlines()
# train_lines = np.load('train_logits.npy')[()]
# val_lines = np.load('val_logits.npy')[()]
num_val = int(len(train_lines))
num_train = int(len(val_lines))
num_anchors = len(anchors)
image_input = Input(shape=(416, 416, 3))
teacher = yolo_body(image_input, num_anchors // 3, num_classes)
teacher.load_weights("model_data/trained_weights_final.h5")
# return the constructed network architecture
# class+5
yolo3 = Reshape((13, 13, 3, 25))(teacher.layers[-3].output)
yolo2 = Reshape((26, 26, 3, 25))(teacher.layers[-2].output)
yolo1 = Reshape((52, 52, 3, 25))(teacher.layers[-1].output)
teacher = Model(inputs=teacher.input, outputs=[yolo3, yolo2, yolo1])
teacher._make_predict_function()
batch_size = 2
i = 0 #step
for logits in data_generator_wrapper(train_lines, batch_size, input_shape,
anchors, num_classes, teacher):
#x , y = dat
#train_logits[i] = logits
#trainY[i] = dat
#print(x.shape)
print(logits[0][1])
print(logits[0][0].shape)
print(logits[0][1].shape)
#print(logits[0][1])
#print( logits[1] )
#print( train_logits[0][0][1].shape)
#print( len( train_logits[0][1] ) )
#print(i)
#print(img.shape)
#print(dat)
i += 1
if i >= 3: #(len(train_lines)//batch_size+1) :
break
'''
def create_model(input_shape,
anchors,
num_classes,
ignore_thresh,
load_pretrained=True,
freeze_body=2,
weights_path='data/yolo_weights.h5'):
"""
创建训练模型
:param input_shape: 输入层尺寸
:param anchors: 锚框坐标
:param num_classes: 类别数
:param ignore_thresh: iou阈值
:param load_pretrained: 预训练控制位
:param freeze_body: 冻结控制层数
:param weights_path: 预训练模型地址
:return: 创建的模型包括模型主体和损失函数
"""
K.clear_session()
image_input = Input(shape=(None, None, 3))
h, w = input_shape
num_anchors = len(anchors)
# [(13, 13, 3, n+6), (26, 26, 3, n+6), (52, 52, 3, n+6)]三种大小
y_true = [
Input(shape=(h // {
0: 32,
1: 16,
2: 8
}[layer], w // {
0: 32,
1: 16,
2: 8
}[layer], num_anchors // 3, num_classes + 5)) for layer in range(3)
] # 这里的3可以按三种尺度的锚框数来统计
model_body = yolo_body(image_input, num_anchors // 3, num_classes)
print(
f"Creat YOLOv3 model with {num_anchors} anchors and {num_classes} classes."
)
# 加载预训练，并冻结非输出层
if load_pretrained:
model_body.load_weights(weights_path, by_name=True, skip_mismatch=True)
print(f"Load weights {weights_path}")
if freeze_body in [1, 2]:
# 冻结除了最后三层外的所有层
num = (185, len(model_body.layers) - 3)[freeze_body - 1]
for i in range(num):
model_body.layers[i].trainable = False
print(
f"Freeze the frist {num} layers of total {len(model_body.layers)} layers"
)
# 构建损失层，计算损失
model_loss = Lambda(yolo_loss,
output_shape=(1, ),
name="yolo_loss",
arguments={
"anchors": anchors,
"num_classes": num_classes,
"ignore_thresh": ignore_thresh
})([*model_body.output, *y_true])
models = Model([model_body.input, *y_true], model_loss)
return models
